1 2 3 4 5 6 7 8 9 10 11 12
=>((a|b|\p{Nd}){1,2}|aaa|bbbb){1,2} bab aaca aaabbbb a0b aa0aaa b0aaa =>(\d{1,3}\.){3}\d{1,3} 1.2.3.4 1.22.333.44 1.2.3 1..2.3